Analytics platforms separate traffic by referrer. When a visitor arrives from a newsletter client the referrer is often stripped, and the visit lands in direct traffic beside every bookmark and typed URL. Five reserved query keys appended to the destination carry the attribution inside the URL itself, so it survives regardless of what the client withholds. The set is fixed, which is why a link tagged with source=newsletter instead of utm_source=newsletter reports as untagged.
| Key | Answers | Status |
|---|---|---|
utm_source | Who sent the visitor — newsletter, google, a partner's name | Needed for the visit not to report as direct |
utm_medium | What kind of channel — email, cpc, social, banner | Paired with source in most reports |
utm_campaign | Which initiative the link belongs to — launch, clearance | Groups the rows you compare |
utm_term | The keyword, for paid search | Optional, and purpose-built for search |
utm_content | Which link of several — banner-a, text-link | Optional; the usual tool for testing two creatives |
Position in the query string has no effect on how a value is read. The spelling does.
Values are compared as literal strings. Email, email and EMAIL are three separate mediums, and a report filtered on one does not contain the others; spring-sale and spring_sale divide the same way. There is no normalisation step and no warning — the numbers simply split. The convention that prevents this is lowercase throughout, one separator chosen for the organisation, and everyone applying the same one.
Values must also be URL-encoded. A raw space is tolerated by most servers but should be written %20, and a raw & inside a value ends the parameter there: utm_campaign=sale & more produces a campaign of sale and a stray key. The generator encodes by default and continues with & when the destination already carries a query string. A newsletter link comes out as:
https://example.com/landing?utm_source=newsletter&utm_medium=email&utm_campaign=summer-sale
Filling the content box appends &utm_content=header-cta. The custom lines append arbitrary key=value pairs after the five reserved ones.
em in one spreadsheet and email in another yields two channels that each look small and neither of which is complete.newsletter in the campaign field collapses a year of sends into a single row. Campaign is for the initiative; the recurring channel belongs in source and medium.No. Source, medium and campaign are the three most reports rely on; term and content are optional and each has a specific purpose. A link carrying only a source still reports differently from an untagged one.
The result carries the key twice, and which value the platform keeps is its own decision. Strip the existing parameters before tagging rather than layering a second set on top.
Parameters do not change a page's content, but they do create additional URL strings. The mechanism to watch is duplication, which the destination's own canonical declaration handles.
Yes, and it is often useful, because the campaign row then aggregates the channels while source and medium break it down. Reusing a value across unrelated initiatives is the problem, not reuse itself.